Michael Brennen:
> The mail from puremail was sent from ip address 66.81.101.50, which reverses
> to 'mx.puremail.com'. A forward lookup on 'mx.puremail.com' results in a
> truncated DNS result and TCP retry, returning 23 ip addresses.
>
> From the remote end's view the 220 return message is delayed by minutes; that
> is how I isolated it to a DNS resolution problem. Running postfix debug on
> that ip address results in the log entries at the end of this mail. The only
> redaction in the log is to remove the specific matches for my local networks.
...
> Dec 4 18:18:27 bilbo postfix/smtpd[3919]: connect from
> mx.puremail.com[66.81.101.50]
This line is logged AFTER the DNS delays. There is no useful
information in what gets logged from here onwards.
You should be able to reproduce DNS delays with Postfix's own
getaddrinfo and getnameinfo utilities, part of the Postfix source
code distribution.
./getnameinfo 66.81.101.50
./getaddrinfo mx.puremail.com
Contact me off-list if you don't have these sources.
These lookups resolve instantly, even on my prehistoric network.
Wietse
